That is a footballers way of letting everyone know he is open to a move or a pay rise
I am not being biased here but unfortunately you are in the same boat as us. If a top class striker has a chance of moving clubs he will look at two things, money and prospects. All the players you mentioned had better prospects and money at the clubs they went to with the exception of Martinez (though Atletico have won the league recently).
Juve, PSG, Bayern, Chelsea, City, all winners or challengers for the title every season and all pay decent money.
Arsenal and United are not a top draw for top strikers at the moment, if any of us get one we should be ecstatic but if not, don't accuse the of manager for not trying.