Employer refusing to tranfer clearance from Scattered Castles

For 10 years my husband has held a TS/SCI through DOD. Within the last 3 years he has worked for the IC and apparently his clearance ended up in SC. (SF86 submitted in 2014. Investigation and full-scope poly completed in Summer 2016)
He was released from his employer in September of 2016. He recently received a job offer from a very large company. We were excited. The job only required a Secret.
After a month of trying to get him to submit a new SF86 to obtain a Secret, and talking to numerous people including the FSO, he gave up and withdrew his acceptance of the job.
Every excuse under the sun was given to him as to why they couldn’t transfer the clearance already in existence. “It takes too long.” “We don’t have someone to do that.” “Why don’t you just fill out the information to get a Secret?” (Why would he give up a high level clearance that he has had for the last 10 years? Odd)
WHY would an employer even look at someone with a clearance at that level, if they weren’t willing to transfer the clearance? Why did they just waste a month and a half of our time?
And _why _is it so difficult to get verification and transference from SC? I though The Intelligence Reform and Terrorism Prevention Act was designed to prevent this mess?

And now you perhaps understand the term “scattered castles.” Each community is its own fiefdom, rarely cooperating with each other for the collective good. Each is king or queen of their respective castle. This situation sounds more like a company with a junior FSO, limited experience, and no site picture of SC. Now to clarify what it means to possess a clearance and this gets tricky.
Nobody really possesses a clearance. People are granted access and clearance eligibility. Eligibility can be granted and withdrawn at will. When your husband left the TS cleared position he was likely debriefed and read out of the programs he worked around. If the facility he worked at was operating under “cover,” even if locals all know the truth…it can be tough to acknowledge you work for the IC without compromising through compilation that the facility was indeed under cover for the IC. Therein lies the reluctance of the IC to share this info. If your husband puts in for the secret clearance he does not “lose” or give up his TS eligibility until such time that the clearance remains inactive, usually 2 years without access. Getting read into and signing a non disclosure agreement for a new program, even at the Secret level doesn’t negate the previous TS. In certain systems I can see a clearance history with various SCI and unique programs where folks held differing clearances and worked different programs.

Thank you @amberbunny. I really appreciate your help. I know he doesn’t really “own” the clearance, We were more concerned about him getting a Secret, and then the company only has to renew at a Secret level and thereby the TS/SCI lapses.
I’m still flummoxed that they hired him in the first place, when the hiring manager knew his level of clearance and where it was, if they had no intention of trying to transfer it. I’m not sure why they even would have offered him the position in the first place.They wasted an extraordinary amount of time and resources including a drug test and background check. It’s all very confusing.