This is more of ignorance of the workings of physics. Most quacks and crackpots like to imagine that physicists are determined to save the status quo of physics ideas, and that they are stuck with what they know and were taught, and very unwilling to work "outside the box". Their biggest "evidence" that they like to point out is that each time they try to come up with their brilliant ideas, some physicists will always try to shoot them down and show why they will not work, etc. This, they argue, stifle creativity, something physicists do not have and unwilling to invoke.
It is unfortunate that such effort in "creativity" is not accompanied by knowledge and, more importantely, logical thinking. There are two major points that can easily trump over such criticism against physicists:
1. If the argument is true, then there is no explanation for the accumulation and the expanding of the horizon of knowledge that we have observed. There are NUMEROUS things that we know of now that we did not know of before. There are many new phenomena that we have either discovered, or can now be accurately described. The fact that the boundaries of our knowledge of the physical world continues to expand is a clear contradiction to the false argument that physicists are only interested in upholding current ideas.
2. Practicing physicists, by definition, study things that either are new, have no current explanation/description, are not completely understood, or beyond the realm of validity of current ideas. This fact is always a surprise to most quacks. We do not study things that are already well-verified! Try getting a research funding to verify Newton's Law under terrestrial condition! Physicists study things that are simply beyond what is known and understood! This is where creativity and imagination come into play. Physicists have to call upon those qualities almost every day in studying complex and difficult ideas and phenomena. However, to know what is new and unexplained, one has to first make sure one knows what is known and understood! Without that, one would not know what is new even if it comes up and bites on one's rear end.
This naturally brings us to an often-used argument made by quacks, that "revolutionary" ideas such as those by Einstein would have been rejected and opposed, very much like the opposition their "theories" are facing. This argument reveals the ignorance and fallacy of how things run in physics and science in general.
While new ideas by Einstein and Planck were initially challenged (as well they should for anyone proposing wildly different and new ideas), it should be pointed out that both of them were proposing ideas not based on ignorance of the subject matter, a fact that is often ignored by quacks. Both Einstein and Planck were masters of the subject. In fact one has to know intimately classical physics to be able to know what was wrong with it. Einstein had to know classical electrodynamics very well (not just from reading a pop-science book) to know how and why it isn't invariant under a galilean transformation. Planck had to know classical statistics very well to know why the Blackbody radiation just simply didn't fit the theoretical description. These are not something one can comprehend simply based on a superficial knowledge of physics.
While physicists at that time were skeptical and critical of both ideas, no one ever argued that Einstein and Planck were putting out their theories based on ignorance of the physics at that time. The same cannot be said with a lot of quackeries found all over the internet.