At least not in the way it is commonly portrayed. Increasing IBD time *is* bad (reduces the number of peers willing to start or re-start running a node). As is increased bandwidth use (especially in internet-third-world countries where data is metered / slow) and to some degree, so is increased database size. But it's certainly not like any node is going to overflow with out-of-memory errors because of spam.
Discussion
Thanks for clarifying.
Exactly. Spamming UTXO set will cause more frequent dumping of RAM cache to disk which takes a long time…I don’t have a numerical estimate but you can estimate it yourself…try repeatedly halving the value of dbcache= in bitcoin.conf and time how long each run takes for initial block download…start at dbcache = 90% of your RAM…I’d bet you’d see a increase in sync time below a certain level and minimal improvement in sync time above a certain level of dbcache.