The non-existent "power of validating nodes" is one of the two weak excuses that pushers for off-chain transactions have propagated in order to push people off the chain ; the other one is that "only soft forks are allowed". These two excuses serve to cripple bitcoin's chain with the blunder Satoshi committed with his 1 MB block limit ; blunder Satoshi thought was easy to adapt if the need was there, but which has been the opportunity to asphyxiate the on-chain transactions to push them to off-chain (or alt-coin) transactions.
Yes, of course, if it is absolutely necessary to have Joe run his node on his old PC with a 320 GB disk in his basement on his 56K modem, then bitcoin is crippled out of the box, true. It wasn't even necessary to make a genesis block in that case, it was sure to fail. Luckily, Satoshi crippled bitcoin, thinking one would be able to remove the limit if needed, not realizing that someone - that is to say, his heir - would see an advantage in crippling bitcoin and keeping this limit, to push his own pet project.
The third weak excuse is that there won't be any subsidies in 120 years so we need a fee market today.