If somebody is willing to pay the fees it hardly can be described as a spam. Bitcoin weakness is its limited blocksize, thats why its not hard to overload the system when many try to use Bitcoin at once. Only about 300,000 Bitcoin transactions can be confirmed daily and there are estimated about 10 million Bitcoiners - but Bitcoin can still work as speculative investment only if people send Bitcoin to the exchange once in while only.
https://bravenewcoin.com/news/bitcoin-spam-attack-stressed-network-for-at-least-18-months-claims-software-developer/