We can't say what every single player felt, but through their union they spoke out in defense of the reserve clause during the 1950's, and I don't think there were many objections from individuals. Like most baseball men, they thought the elimination of reserve rights would mean "the end of baseball as we know it." Events have shown that this expectation was perhaps somewhat exaggerated, but can anybody consider the enormous dislocations, instability and tumult since the Messersmith decision and say it was completely mistaken?
But the ten-day clause was certainly not a benefit to individual players. It did guarantee the player a week and a half's severance pay if he were released, but at the same time it granted the club the right to terminate on a week and a half's notice the same contract that bound the player for an entire season, or for three seasons in the case of a contract such as the one Jackson signed in 1920. The ten-day clause did not provide the least bit of security for players, except in the sense that one might take the broad and speculative view (as most baseball people in fact did) that the system embodied in the standard contract was necessary to preserve the stability of the baseball world, enable weaker clubs to survive and thereby provide employment to many of the players, whatever the inconvenience or outright harm might come to particular players in individual cases. With the ten-day clause removed the standard contract would become something rather more like a real contract, that is, a document granting rights and imposing responsibilities on both sides, instead of giving practically all the rights to the clubs.
The baseball contract has almost always proven impossible to enforce legally, and there are several reasons for this, but one is that the the ten-day clause in combination with the reserve clause made the document so one-sided ("lacking in mutuality" is the legal term) that the courts literally would not regard it as a contract at all. When the Giants went to court to stop John Ward from disregarding the reserve clause and jumping to the Players League in 1890, the judge hearing the court remarked:
"We have the spectacle presented of a contract which binds one part for a series of years and the other party for ten days."
The Giants were denied injunctions against Ward and Buck Ewing, and so it has gone almost every other time a club's contract right to a particular player has been brought up in court.
Binding one side for life and the other for a week and a half, imposed as a standard document upon the players without any negotiation as to its form, the standard baseball contract with the ten-day and reserve clauses intact was in fact not a contract, a document that could be enforced in court. It was the embodiment of an agreement among the clubs that, first, they would each give up their own legal right to contract with respect to at least fifteen-sixteenths of the number of professional players of any value at a given time; and, second, they would ignore the right to contract of every one of the players.
“Money, money, money; that is the article I am looking after now more than anything else. It is the only thing that will shape my course (‘religion is nowhere’).” - Ross Barnes