This is partially true, but with advancements in power and technology (see 'are 12's the new 13's', and the RB20 250+ club threasa), it is more and more feasible.
Because people can just copy what these people have done, with out the trial and error, and with out money spent on development.
What I see as the problem, is people who upgrade the engine, but leave little attention to suspension, reliability, tyres, brakes etc. - the supporting mods
But I do agree, TFNF and other associated publicity has got some people into the import scene who should not necesarily be there