Is getting a pilot job at a major airline hard (even with the required flight hours)?

Yes, it IS hard. Only 50-60% of all professional pilots ever work for a major airline. Here are some of the things that can work against you being hired:

A history of written test or flight test failures during training
A failure of a competency check in any flying job
A history of certain medical problems or emotional problems
Bad credit history - not paying bills reliably
Bad driving record - speeding and other moving violations
Poor employment history. Getting fired or too much job-hopping
Problems with the law. Felonies or misdemeanors.
Personality issues. Don't interract well with others. Excitable, impatient or anger easily.
Poor flying record - accident, incident, violation or letter of warning
Age. The hiring window is approximately 30-45. The average new-hire age is 34.
Inadequate education. In the USA you'll need a 4 year degree to be competitive
Any indictments or arrests involving drugs or alcohol
Poor interview skills, bad communication skills or you comport yourself poorly
Overweight, anorexic, sloppy unprofessional appearance or visible tattoos.
Unverifiable flight time or employment records.
Weak instrument flying skills in simulator evaluation

They do a very thorough background check. Minimum 10 years. Some things, such as legal records, pilot training records and airman medical records are permanent, lifetime records. One mis-step can cost you a career with a major airline. FACT

They may have loads of reasons not to, like not needing any additional pilots when you apply.

Yes it is, for all of the reasons given in another answer and the fact that there will be dozens of similarly qualified applicants for each vacancy.

It is the ultimate ''Buyers Market''!

Yes it is.