"They (the Indian players) were not properly prepared to deal with an England team that are playing top cricket at the moment," he was quoted as saying in ''The Sunday Times''.
"After winning the World Cup in April, they played in the Indian Premier League (IPL) and then toured the West Indies, winning against the inexperienced side. So, they thought playing England would also be easy," Kapil said.
England beat India 4-0 in the four-match Test series to hand the visitors their worst defeat in England after the 5-0 whitewash in 1959 - which included three innings defeats and others by 171 runs and eight wickets.
Kapil also dismissed the issue of fatigue from non-stop cricket in recent years and said there was just no proper planning for a tough tour of England.
"The bowlers have to work harder," said Dev in comments on the Indian players'' bowling against England.
"There is no short-cut to success. Only with proper training can they expect to do well. They were not fully prepared," he said.
Kapil also dismissed talks that the Indian players would have shown more guts if it had been a series involving their cash-rich IPL clubs, and pointed out that IPL and Twenty20 have given many youngsters chance to get noticed.
He does not advocate wholesale changes to the Indian team.
"I don''t know who can come in. The board must decide. But proper planning is important," he said.